Long-Term Monitoring of Brain Dopamine Metabolism In Vivo with Carbon Paste Electrodes

This review focuses on the stability of voltammetric signals recorded overperiods of months with carbon paste electrodes (CPEs) implanted in the brain. The keyinteraction underlying this stability is between the pasting oil and brain lipids that arecapable of inhibiting the fouling caused by proteins. In brain regions receiving a significantdopaminergic input, a peak due to the methylated metabolites of dopamine, principallyhomovanillic acid (HVA), is clearly resolved using slow sweep voltammetry. Although anumber of factors limit the time resolution for monitoring brain HVA concentrationdynamics, the stability of CPEs allows investigations of long-term effects of drugs, as wellas behavioral studies, not possible using other in-vivo monitoring techniques.